Leukotriene cross reactions
Question:
2/11/2019
I am doing an oral desensitization to aspirin for AERD and would like patient on a leukotriene-modifying drug, however she has hives with montelukast. Is there cross reactivity between zafirlukast, montelukast and zileuton? If there is could I do skin testing or graded challenge?
Answer:
Allergic reactions to montelukast is rare but there are case reports (1). Due to rare occurrence of adverse effects associated with montelukast there is very little information about options. Structurally there are more similarities between zafirlukast and montelukast than between zileuton and montelukast. Whether these structures have any influence on the adverse effect is not known. Personally, I have cared for patients who did not tolerate montelukast and did not tolerate zafirlukast but these events were most assuredly not immunologic but more of an intolerance. If the hives associated with montelukast were not associated with other features of anaphylaxis, I would favor a graded challenge with zafirlukast but think zileuton is an option as well. In my experience, zileuton tends to be more expensive and sometimes not feasible with certain health plans.
In summary, I suggest challenging with zafirlukast, one half tablet and 30-60 minutes later administer the second half. I would then start zafirlukast bid. I would also consider a graded challenge to montelukast hoping that the urticaria was an idiosyncratic, nonreproducible reaction, depending on the severity of the urticaria. I would use zileuton if I had problems with the above.
1. Minciullo, Paola L., et al. "Montelukast-induced generalized urticaria." Annals of Pharmacotherapy 38.6 (2004): 999-1001.
I hope this information is of help to you and your practice.
All my best.
Dennis K. Ledford, MD, FAAAAI